title: Galanin receptor/Neuropeptide Y receptor interactions in the dorsal raphe nucleus of the rat.
abstract: The aim of this study was to evaluate by quantitative receptor autoradiography the interactions between Neuropeptide Y Y1 (NPY Y1) and Galanin (GAL) receptors in the dorsal raphe nucleus (DRN) where both GAL receptors and NPY Y1 receptors exist. The ability of the GAL receptor antagonist M35 to block the GAL action was also evaluated. Double immunocytochemical staining of 5-hydroxytryptmine and c-Fos and stereology techniques were used to study the specific cell activation in the DRN after the intracerebroventricular coinjections of GAL and the NPY Y1/Y5 agonist [(125)I] Leu(31),Pro(34)PYY. GAL (0.3 nM) decreases [(125)I] Leu(31),Pro(34)PYY binding in the DRN by 48% (p < 0.01) as shown by quantitative receptor autoradiography. This effect was reversed with the GAL receptor antagonist M35. Intracerebroventricular coinjections of NPY Y1/Y5 agonist and GAL reduced the c-Fos expression in the serotoninergic cells induced by the NPY Y1/Y5 agonist in DRN. These results indicate the existence of antagonistic interactions between GAL receptors and NPY Y1 receptors in the DRN that may be of relevance in mood disorders.
authors.affiliation: Department of Physiology, University of Málaga, Málaga 29080, Spain. zaida@uma.es
authors.forename: Zaida
authors.initials: Z
authors.lastname: Díaz-Cabiale
authors.forename: Concepción
authors.initials: C
authors.lastname: Parrado
authors.forename: Manuel
authors.initials: M
authors.lastname: Narváez
authors.forename: Araceli
authors.initials: A
authors.lastname: Puigcerver
authors.forename: Carmelo
authors.initials: C
authors.lastname: Millón
authors.forename: Luis
authors.initials: L
authors.lastname: Santín
authors.forename: Kjell
authors.initials: K
authors.lastname: Fuxe
authors.forename: José Angel
authors.initials: JA
authors.lastname: Narváez
mesh_terms: D000818:Animals; D019004:Galanin / Q000008:administration & dosage / Q000378:metabolism; D007276:Injections, Intraventricular; D008297:Male; D011485:Protein Binding / Q000502:physiology; D011903:Raphe Nuclei / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044088:Receptors, Galanin / Q000819:agonists / Q000378:metabolism*; D017476:Receptors, Neuropeptide Y / Q000819:agonists / Q000378:metabolism*
chemical_list: D044088:Receptors, Galanin; D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; D019004:Galanin